Equipment layout for fiber distribution hubs

ABSTRACT

A fiber distribution hub includes a panel mounted within and pivotally movable relative to an enclosure. One or more connector holders are carried by the panel. The connector holders are provided at a connector storage location. The connector holders have a construction different than a functional fiber optic adapter.

RELATED APPLICATIONS

The present application is a continuation of application Ser. No.11/203,157, filed Aug. 15, 2005, now U.S. Pat. No. 7,369,741, which is acontinuation-in part of application Ser. No. 10/991,135, filed Nov. 17,2004, now U.S. Pat. No. 7,200,317, which is a continuation-part ofapplication Ser. No. 10/714,814, filed Nov. 17, 2003, now U.S. Pat. No.6,983,095, the contents of both are incorporated herein by reference intheir respective entireties. The present application also claimspriority, under 35 U.S.C. §119(e), to provisional application Ser. No.60/672,502 filed Apr. 19, 2005, the content of which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to optical communicationnetworks, and more particularly to devices and techniques for hingedparking of unused connectors in an enclosure used in a passive opticalcommunications network.

BACKGROUND OF THE INVENTION

In Fiber-to-the-Premises broadband network applications opticalsplitters are used to split the optical signals at various points in thenetwork. Recent network specifications call for optical splitters to beincorporated in fiber distribution hubs (FDHs) which are re-enterableoutdoor enclosures. These enclosures allow easy re-entry for access tooptical splitters allowing splitter ports to be utilized effectively andfor additional splitter ports to be added on an incremental basis.

In typical applications to date, optical splitters are providedprepackaged in optical splitter module housings and provided withsplitter outputs in pigtails that extend from the module. The splitteroutput pigtails are typically connectorized with high performance lowloss simple connector (SC) and/or LC connectors. This optical splittermodule, or cassette, provides protective packaging for the opticalsplitter components in the housing and thus provides for easy handlingfor otherwise fragile splitter components. This approach allows theoptical splitter modules to be added incrementally to the FDH, forexample, as required.

A problem may arise due to the lack of protection and organization ofthe connectorized ends of the splitter output pigtails. For example,these pigtails can sometimes be left dangling in a cable trough orraceway within the enclosure. Leaving an optical component, such as ahigh performance connector, exposed in an open area leaves itsusceptible to damage. These high performance connectors if damaged cancause delays in service connection while connectors are repaired.Leaving connectorized splitter output pigtails dangling in a cablingtrough also exposes them to dirt and debris in the cabling trough. Incurrent network deployments it may be important to maintain cleanoptical connectors to maximize the performance of the network.

In addition, fiber pigtails in the current art may be organized in amanner that is not conducive to rapid service delivery. In many casessplitters may have sixteen or thirty-two output pigtails bundledtogether making it difficult to find a particular pigtail. Also thebundle of loose hanging pigtails can easily become entangled and/ordamaged causing further delays in service delivery. These tangles cancause congestion and, in some cases, result in bend induced loss on thepigtails, causing lower system performance.

To solve some of these issues a separate storage tray or enclosure hasbeen utilized to take up slack and/or store and protect splitter outputpigtail connectorized ends. However, these auxiliary devices tend totake up additional space and often obscure pigtails in an enclosuremaking it difficult for a linesman to locate a particular pigtail and/orconnector. As a result, delays may occur in deployment of new subscriberconnections depending on how much time is required to access the fiberpigtails in the enclosure. Thus, there is a need for a solution thatprovides convenient storage for fiber pigtails and/or connectors anddoes not take up additional space in the enclosure. The solution shouldprovide direct access to and identification of fiber pigtails and/orconnectors.

Finally current methods tend to result in a disassociation of thesplitter module from the splitter output pigtail end. This usuallyresults because the pigtail, once deployed, gets lost in the midst ofother pigtails in the fiber jumper trough. When subscribers are takenout of service it is desirable to disconnect the splitter output andredeploy or store it for ready redeployment. It is further desirable foradministrative purposes to maintain association of splitter module tosplitter output pigtails so that resources are used effectively overtime.

FDHs may benefit from devices and techniques that can be adapted tofacilitate the organization of fiber pigtails and fiber pigtailterminations as well as protecting sensitive optical components when notin use. The devices and techniques should also facilitate easy access topigtails and connectors so that subscribers may be efficiently connectedand disconnected from the network. The devices and techniques shouldalso group pigtails and connectors in a manner that allows them to beassociated with a particular splitter module.

SUMMARY OF THE INVENTION

In accordance with an implementation, a parking adapter is provided. Theparking adapter may include a plurality of receptacles configured toreceive a like plurality of connectors, where each connector isassociated with an optical fiber. The parking adapter may include a dustcap post configured to receive a connector dust cap associated with atleast one of the plurality of connectors. The parking adapter mayinclude a mounting device configured to removeably couple the parkingadapter to a panel.

In accordance with another implementation, an enclosure adapted for usein an optical communications network is provided. The enclosure mayinclude a first access door pivotally supported on the enclosure andadapted to facilitate access to an interior portion of the enclosurewhen the first access door is in an open position. The enclosure mayinclude a hinged panel adapted to reside in the interior portion of theenclosure when the first access door is in a closed position. The hingedpanel may also be adapted to support a parking adapter configured toreceive a connector associated with an optical fiber routed in theenclosure, where the connector is received when the optical fiber is notassociated with conveying an optical signal to a destination device. Theparking adapter may also be configured to receive a connector dust capassociated with the connector or an adapter dust cap associated with anadapter. The enclosure may include a subscriber termination area adaptedto provide the optical signal to the destination device.

In accordance with still another implementation, a method forconfiguring an enclosure in an optical communications network isprovided. The method may include removing a connector from a parkingreceptacle associated with a parking adapter, where the parking adapteris associated with a hinged panel. The method may include supporting aconnector dust cap on a dust cap post associated with the parkingadapter, where the connector dust cap is associated with the removedconnector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates schematically a broadband access network, forexample, a fiber-to-the-premises (FTTP) network using passive opticalnetwork (PON) components in accordance with a preferred embodiment ofthe present invention;

FIG. 2 illustrates schematically further details of an FTTP network inaccordance with a preferred embodiment of the present invention;

FIG. 3A illustrates an optical splitter module in a fiber distributionnetwork having connectorized pigtails in accordance with a preferredembodiment of the present invention;

FIG. 3B illustrates an exemplary embodiment of an optical componentmodule in accordance with a preferred embodiment of the invention;

FIG. 4A schematically illustrates the installation of the opticalsplitter module pigtails in accordance with a preferred embodiment ofthe present invention;

FIG. 4B schematically illustrates the service connection configurationof the optical splitter module in accordance with a preferred embodimentof the present invention;

FIGS. 5A and 5B schematically illustrate the installation of the opticalsplitter module pigtails and the service connection configuration of theoptical splitter module, respectively, in a network having modulesadjacent to each other in accordance with a preferred embodiment of thepresent invention;

FIGS. 5C and 5D schematically illustrate the service connectionconfigurations between adjacent fiber distribution hubs in accordancewith alternate preferred embodiments of the present invention;

FIG. 6A illustrates an embodiment of a single width splitter modulealong with an embodiment of a double width module in accordance with anaspect of the invention;

FIGS. 6B-6H illustrate exemplary splitter module arrangements inaccordance with an aspect of the invention;

FIGS. 7A-7E illustrate views of the fiber distribution hub in accordancewith preferred embodiments of the present invention;

FIG. 8 illustrates a view of the internal components of a fiberdistribution hub enclosure in accordance with a preferred embodiment ofthe present invention;

FIG. 9 illustrates a schematic view of a fiber distribution hubenclosure having a side-by-side equipment configuration in accordancewith a preferred embodiment of the present invention;

FIG. 10 illustrates an embodiment of an FDH employing a hinged chassisin accordance with an aspect of the invention;

FIG. 11A illustrates an embodiment of an FDH utilizing a splitenclosure;

FIGS. 11B-11G illustrate various aspects and embodiments of an FDHhaving a split enclosure;

FIGS. 11H and 11I illustrate an exemplary method for using an FDHenclosure having a split housing;

FIG. 12A illustrates an embodiment of a utility pole mounted FDH havingfall restraint hardware integrated therewith;

FIG. 12B illustrates a method for accessing and elevated FDH;

FIG. 13 is a flow chart illustrating a method for installing andconnecting optical splitter module pigtails in accordance with apreferred embodiment of the present invention;

FIG. 14A illustrates a preferred embodiment of a single hinged parkingpanel for use in fiber distribution hubs;

FIG. 14B illustrates a preferred embodiment of a dual hinged parkingpanel for use in fiber distribution hubs;

FIG. 15 illustrates an exemplary implementation of an equipmentenclosure employing hinged parking;

FIG. 16 illustrates an exemplary implementation of a parking adapterthat may be used in conjunction with first hinged door and/or secondhinged door;

FIG. 17 illustrates an exemplary parking adapter including an adapterdust cap and connector dust cap along with a parked connector having anoptical fiber associated therewith;

FIG. 18 illustrates an exemplary enclosure having stationary parkingadapters;

FIG. 19 illustrates an exemplary method for configuring an enclosurewith hinged parking; and

FIG. 20 illustrates an exemplary method for connecting a subscriber toan optical signal associated with an enclosure employing hinged parking.

DETAILED DESCRIPTION OF THE INVENTION

As generally described herein, an optical splitter module that isequipped with adapters for storing connectorized optical splitterpigtail ends is disclosed. Adapters are administratively located on theoptical splitter module bulkhead, for example, but not limited to, inoctal count arrangements ideally suited to identify splitter portshaving sixteen or thirty-two output ports. The adapters in accordancewith preferred embodiments are used to store or stage the connectorizedends of the optical splitter for rapid location, identification, easyaccess and removal of pigtail output ends. In accordance with preferredembodiments, the optical splitter outputs extending from the bulkhead onthe module are wrapped back and secured to adapters on the splitterbulkhead. The preferred embodiments also include methods for installingoptical splitter modules and associated fixed length output pigtails,storing the connectorized ends of the pigtails in a position ready fordeployment and then individually connecting the splitter outputs asrequired to connect service to subscriber terminations.

FIG. 1 illustrates, schematically, a broadband access network 10, whichfor example, can be a Fiber-to-the-Premises (FTTP) network using passiveoptical network (PON) components in accordance with a preferredembodiment of the present invention.

FIG. 1 includes an optical line terminal (OLT) 12, a voice input 14 froma service network, a data input 16 from a service network, a video input18 from a service network, a wavelength division multiplexed fiber 20, apassive optical splitter 22, an optical network terminal (ONT) 24 and26, a residence and an office building 28.

Network 10 employs OLT 12 which receives input data streams from servicenetworks. By way of example, OLT 12 may receive voice input 14, datainput 16 and video input 18. OLT 12 may then output a multiplexed datastream over one or more optical fibers 20. In an embodiment, OLT 12 mayoutput voice at a wavelength on the order of 1490 nm, data at awavelength on the order of 1310 nm and video at a wavelength on theorder of 1550 nm. Optical fiber 20 may convey data using, for example,wavelength division multiplexing (WDM) to a passive optical splitter(POS) 22. POS 22 may receive data by way of a single fiber (the inputfiber) and split the data across a plurality of output fibers. Forexample, POS 22 may split incoming data across 8, 16, 32, or more outputfibers. In a preferred embodiment, each output fiber is associated witha respective end user such as a residential end user 27 or a commercialend user in office building 28. End user locations may employ opticalnetwork terminals (ONTs) 24, 26 for accepting multiplexed data andmaking it available to the end user. For example, ONT 24 may act as ademultiplexer by accepting a multiplexed data stream containing voice,video and data and demultiplexing the data stream to provide a separatevoice channel to a user's telephone, a separate video channel to atelevision set and a separate data channel to a computer.

The architecture described in conjunction with FIG. 1 can be a point tomulti-point PON construction, which utilizes, for example, 1:32splitters at a fiber hub enclosure within a distribution area. Thearchitecture can be fiber rich 1:1 distribution between the fiber huband a customer's premise or the architecture can be diluted 1:X where Xis an integer larger than 1. The broadband services capability ofnetwork 10 for distributing source information may include, for example,data signals (622 Mbps×155 Mbps (shared)), and video signals (860 MHz,˜600 analog and digital channels, high definition television (HDTV), andvideo on demand (VOD)). Source information may consist of data, such as,for example, voice or video that originates at a source such as atelecommunications service provider, hereinafter service provider.Signaling may be accomplished using wavelength division multiplexing(WDM) and fiber sharing. Network 10 can include optical networkterminals 26 that are scalable, provide high bandwidth, multi-serviceapplications that serve residences and small to medium sized businesses.Network 10 includes passive components that are located outside theplant, i.e. outside the service provider's building, and require minimalmaintenance, since active components such as amplifiers are notrequired.

The broadband access network 10 includes digital subscriber plug-in linecards that have a broadband terminal adapter configured for receiving adigitally multiplexed broadband data stream and outputting a pluralityof demultiplexed broadband data streams for the respective subscriberloops.

FIG. 2 illustrates an alternative implementation of an optical broadbandaccess network 50. Network 50 may include a circuit switch/OLT 52, anSAI, a splitter hub 54, residential ONTs 56, small business ONT 58,office park ONT 60, splitter 64, and fiber-to-the-premises (FTTP) 62. InFiber-to-the-Premises broadband network applications optical splitters64 are used to split the optical signals at various points in thenetwork. In FTTP network 50 optical splitters are typically located inboth indoor and outdoor environments including a Central Office/HeadEnd, environmentally secure cabinets, enclosures or fiber dropterminals. In some outdoor applications, optical splitters have beendeployed in tightly sealed environmental enclosures that are not easilyre-enterable. Preferred embodiments include optical splittersincorporated in fiber distribution hubs 54 which are re-enterableoutdoor enclosures. These enclosures allow easy re-entry by linesmen orother service personnel for access to optical splitters 64 allowingsplitter ports to be utilized effectively and for additional splitterports to be added on an incremental basis.

Preferred embodiments of the present invention may receive data fromoptical splitters that are provided prepackaged in optical splittermodule housings that are mounted in a fiber patch panel to facilitaterouting of jumpers interconnected from fibers in adjacent subscriberports to the splitter outputs. This optical splitter module, orcassette, provides protective packaging and thus easy handling forotherwise fragile splitter components. The optical splitter modules canbe added incrementally to the patch panel.

FTTP broadband networks are designed to achieve low optical insertionloss in order to achieve maximum network reach from electronics havingfixed power output. Each optical component and subsystem utilized in thenetwork is optimized to provide minimum insertion loss. The optical lossbudget in a preferred embodiment is approximately 23 to 25 dB with 1:32passive splitting. The components and factors contributing to theoptical loss include splitters (1:32, single or cascaded), WDMs,connectors (optical line terminal (OLT), FDF, splitters, drop, ONT),fiber attenuation (at least three wavelengths: 1310 nm, 1490 nm, 1550nm), and splicing.

Splitter hub 54 may serve on the order of 128 splitter ports/premises.It includes multiple distribution cables, connectorized or fusionspliced between splitter and distribution hub 54. The splitter hubs usedin conjunction with preferred embodiments are pole or ground mountable.The drop terminals can be with or without splitters and include variousnumber of drops, both aerial and buried.

Splitters 64 may be deployed by way of splitter hub 54 or they may bedeployed in smaller enclosures. A fiber drop terminal 65 is often usedin conjunction with a utility pole 63 (FIG. 2). Utility pole 63 may beused to support conventional copper wire strands such as those used forplain old telephone service (POTS) and those used for cable television(CATV). For example, POTS strands may consist of a plurality of twistedpairs and CATV may consist of coaxial cables. Utility pole 63 may alsosupport optical fiber bundles such as those used for delivering FTTPservices. A fiber drop terminal 65 may be attached to utility pole 63and communicatively coupled with one-or-more of the optical fiberscontained in a strand. Fiber drop terminal 65 may be spliced to opticalfibers using techniques known in the art. For example, fiber dropterminal 65 may be spliced to an optical fiber at a manufacturing orassembly plant at a predetermined location on a strand, or fiber dropterminal 65 may be spliced to an optical fiber in the field by alinesman, or other crafts person, at a determined location.

Fiber drop terminals are used to interface between distribution cablesand drop cables in a Passive Optic Network (PON) application. The fiberdrop terminal 65 typically is installed by splicing a multi-fiber cableat a branch point in a large fiber count distribution cable. Fiber dropterminals may typically consist of 2, 4, 6, 8 or 12 fibers and in someinstances even more fibers. A single cable may be used as the input tothe terminal containing the fibers with the aforementioned counts. Byway of example, a feed cable may have a central tube housing a pluralityof individual optical fibers. Inside fiber drop terminal 65 themulti-fiber feed cable is separated into individual fibers and thenterminated on individual rugged outdoor connector/adapters located onthe exterior surface of the enclosure. Fiber drop terminal 65 is thusused to stage the PON cabling system near premises locations, such as aresidence or office building, so that when a subscriber requests servicea simple connectorized drop cable can be quickly connected between thefiber drop terminal and the Optical Network Terminal (ONT) at the home.

In some embodiments, optical connectors are used in the network toprovide the desired flexibility however they are restricted to thosepoints in the network where flexibility is absolutely required. Opticalconnectors are required to provide flexible access to optical splitteroutputs. The preferred embodiments of the present invention provideconnector flexibility and yet minimize optical loss using the opticalsplitter module with connectorized pigtails. The pigtails may havestandard SC or LC type connectors on the ends.

FIG. 3A illustrates an optical splitter module 100 in a fiberdistribution network having connectorized pigtails in accordance with anexemplary embodiment. Module 100 may include essentially any number ofoutput pigtails; however, typical deployments will utilize either 16 or32 outputs per splitter module. The module 100 includes a bulkheadfaceplate 102 having storage receptacles 112. In one embodiment, theoptical splitter module 100 provides for a high density ribbon cablingharness 106 to protect the splitter outputs extending from module 100.The optical splitter module ribbon harness 106 is secured to module 100with a strain relief mechanism 104 to provide high pull strength andbend radius control. The compact nature of the ribbon harness 106 allowsfor higher packing density and better space utilization in the cablingtrough. The module harness is converted to individual pigtails withconnectors to allow splitter outputs to be administered and rearrangedindividually.

Module 100 may be equipped with either half non-functional adapters orfull functioning adapters as a means for storing pigtail ends. Inpreferred embodiment, the half non-functional adapters are used inapplications not requiring fiber optic terminators other than forstorage functionality. The full functional adapters are used inapplications requiring connection of fiber optic terminators to theoptical splitter output port. Access to the pigtail ferrule tip may berequired for attaching fiber optic terminators to eliminate undesirablereflections caused by unterminated connectors. The module provides ahome position from which optical splitter output pigtails can bedeployed from when placed into service and where the splitter outputpigtails can be returned to once taken out of service. Thisadministrative use of adapters provides protection for the connectorizedpigtails ends, maintains cleanliness of the connector ends, and enablesrapid service connection and deployment.

The embodiments of the present invention address configuring a fiberdistribution hub with optical splitter modules having fixed lengthconnectorized pigtails. One aspect determines where to position theoptical splitter modules relative to other fiber terminations needingaccess to the optical splitter ports. The embodiments also provide forinstalling pigtails in a configuration that requires minimal pigtailrearrangement and slack yet allows for enough slack to reach any of thefiber terminations that require access to splitter ports. The methods ofinstalling optical splitter module pigtails include determining how toroute the pigtails in order to provide an optimal routing scheme thatdoes not become congested and wherein slack can be controlled within setlimits of the enclosure. The methods may include making all pigtails thesame length for ease of manufacturing and ordering by the customer.Splitter modules all having the same pigtail length also allow ease offlexibility for allowing a splitter module to be installed in anyavailable slot within the patch panel without regard to sequentialorder. While fixed length pigtails are preferred for many applications,embodiments are not limited thereto. If desired, variable lengthpigtails may also be used.

One embodiment for installing the splitter module pigtails also providesfor fiber management in the enclosure so that rearrangement and chumdoes not interfere with management of the pigtails. To accomplish this,the slack and any chance of blocking access because of fiberentanglement is minimized. Some embodiments allow for churn over timeincluding initial pigtail storage, service connection, servicedisconnection and repeat storage to provide ready access to pigtails forfuture use. The method can be non-blocking and non-congesting forjumpers routed into cable pathways and fiber patch panels. The methodcan be fully contained within the confines of the enclosure.

FIG. 3B illustrates a view of the optical component modules (OCM) 107A-Din module chassis frame 101 a fiber distribution hub enclosure inaccordance with an embodiment of the present invention. The FDHconfiguration provides for fiber management hardware on one side of thecabinet. This allows fiber jumpers to be routed between the terminationshelf and the splitter shelf. Excess slack can be managed on the side ofthe cabinet using slack loops.

In accordance with one embodiment, OCM modules 107 A-D can also beequipped with pigtails 105 to reduce the number of connections in thenetwork. The modules shown in FIG. 3B may each contain a 1×32 splitterwith pigtails provided on the input and 32 outputs. The connectorizedends of the pigtails are stored on bulkhead adapters 103 on the front ofthe module. These storage adapters provide a familiar locating schemefor spare pigtails so that connector ends can be quickly identified andconnected to distribution fibers. The spacing on the adapters is thesame as on standard connector panels.

In some embodiments, OCM modules can also be equipped with standardterminators. Modules terminated with bulkhead adapters may be equippedwith terminators on the front of the module. Modules connected viapigtails and equipped with storage adapters are equipped withterminators on the rear of the panel.

FIG. 4A schematically illustrates the installation of the opticalsplitter module pigtails 138 in accordance with an embodiment of thepresent invention. An embodiment of the present invention includes acabling installation layout 125 for FDH 127 including splitter modules132 incrementally installed on a shelf 129 adjacent to a subscribertermination field 128. The connectorized pigtails 138 from the splittermodules 132 having fixed identical length are routed in acircumferential path 130 surrounding the subscriber termination field128. The connectorized ends of the pigtails 138 are stored at a positionon the front of the splitter module 132 using storage receptacles 134.The layout in accordance with a preferred embodiment employs a fanthrough placement so that the splitter module pigtails can be installedwithout disturbing installed pigtails already connected to subscribertermination field 128. This installation layout in accordance with apreferred method of the present invention also ensures that the splittermodule 132 can be preconfigured with the pigtail connectors 135 in thestorage position and left in the storage position throughout the pigtailinstallation process.

FIG. 4B schematically illustrates the service connection configuration150 of the optical splitter module in accordance with an embodiment ofthe present invention shown in FIG. 4A. The embodiments of the presentinvention include a service connection method to connect a subscriberinto service by first disconnecting an individual splitter outputpigtail 138 from the storage position in splitter module 132 and thenrouting the pigtail to the desired subscriber port 152. Since thepigtail harness has been preconfigured and routed circumferentiallyaround the subscriber termination, the pigtail 138 inherently reachesany of the desired subscriber ports within the target population bysimply reducing the circumferential path distance. By reducing thecircumferential path the pigtail slack exhibits additional slack. Theadditional slack may be taken up using slack-half loops in the verticalchannel 153A, B, or pigtail channel, where the pigtails are routed. Therandom nature of connecting splitter output pigtails to subscriber ports152 may result in a group of various size half-loops 154 that aremanaged in the vertical channel 153A and 153B within the confines ofcabinet 149.

FIGS. 5A and 5B schematically illustrate the installation of the opticalsplitter module 132 pigtails and the service connection configuration ofthe optical splitter module 132, respectively, in a network havingmodules adjacent to each other in accordance with an embodiment of thepresent invention. An embodiment of the present invention includes amethod to connect subscriber ports that are in an adjacent field but notinitially contained within the circumference of the splitter pigtailharness 178. In this extension the splitter output pigtail is routed tothe adjacent field 180 which by virtue of a juxtaposed position has apath at the same distance to the subscriber port within thecircumference. The subscriber ports 192 (FIG. 5B) in the adjacent fieldalso are assigned randomly therefore the resultant slack is managedusing a group of various size half-loops in the vertical channel 176.

FIGS. 5C and 5D schematically illustrate the service connectionconfigurations 194, 206 of the termination and splitter fields inadjacent fiber distribution hubs in accordance with a preferredembodiment of the present invention. The pigtails 198, 208 of the leftmodule 196, 214 are routed circumferentially clockwise while the rightpigtails 204, 210 of the module 202, 216 are routed circumferentiallycounterclockwise in a preferred embodiment. The fiber distribution hubsin this embodiment are located adjacent to one another, each having asplitter shelf with splitter modules and a termination shelf. Thecounter rotating feed provides for routing of the splitter module outputpigtails circumferentially around the subscriber termination fields. Thepigtail slack is stored in the vertical channels 200, 212.

An embodiment includes a method of removing a splitter pigtail from asubscriber port 192 and either redeploying that output pigtail to a newsubscriber port or storing the pigtail back to the original storageposition at the splitter module 132. The method is non-blocking andnon-congesting due to the planned slack management.

Most embodiments of optical splitter modules 132 used in FDH 127 mayhave 16 output ports or 32 output ports depending on a particularnetwork configuration which may include considerations for an opticalbudget associated with the optical splitters and associated networkreach.

FIG. 6A illustrates a single width module 222 having a width (W1) 230along with a double width module 224 having a width (W2) 232 that is onthe order of twice that of WI 224. Optical splitter modules 222, 224 mayhave a physical configuration where output ports are terminated on thebulkhead faceplate 227, 229 using connectors and/or receptacles 228,238, 240, or alternatively, with output ports in the form of pigtails138 extending from the bulkhead faceplate and wrapped back and staged onstorage ports 226, 234, 236 located on the faceplate as shown in, forexample, FIG. 4A. In at least one design implementation, a 16 portmodule 222 may be deployed as a single width module W1 230 having outputports or storage ports arranged in a single column on the faceplate 227.And, according to the same design implementation, a 32 port module 224is a double width W2 232 module having output ports 234 or storage portsarranged in two columns of sixteen each on the faceplate 229.

When used with pigtails and storage ports, the multi-fiber pigtailharness and associated breakout to individual pigtails may consume spacein the enclosure to store the protective breakout device that convertsfrom multi-fiber cables to individual fiber pigtails. The space forstoring the breakout device, or transition, 131 (FIG. 4A) is designed toallow either breakouts from two sixteen output port modules 222 or onethirty-two output port module 224 to be used. Furthermore the space forstoring the transition 131 may be located at a fixed distance along acircumferentially routed splitter output harness. Therefore the space inthe chassis allocated for mounting splitter modules that corresponds tothe fixed storage space for the transition 131 should allow only twosixteen output port splitter modules 222 or one thirty-two output portsplitter module 224 to be installed.

In certain situations, it may be desirable to employ a configurationutilizing an installation sequence wherein a 16 port module 222 isinstalled interstitially between two 32 port modules 224 with no spacebetween adjacent modules. Such a configuration can pose problems ifinadequate space is provided for accommodating the transition 131.Examples of problems that occur may include blocking and congestion. Apair-wise installation of a single width module 222 (e.g. a 16 outputport module) in a double width slot can be utilized to preservecorrespondence of equal length cabling harness transitions 131 which arestored and secured remotely from a splitter module in a designatedstorage area 133 of enclosure 127.

Embodiments of the invention make use of structures and methods thatalone, or in combination, dissuade a user from installing a 32 portdouble width module 224 immediately adjacent to a 16 port single widthmodule 222 in situations where single width 16 port modules have notbeen installed in pairs, i.e. two 16 port modules installed immediatelyside-by-side. Techniques utilized in preferred embodiments, employ anautomatically indexed latch to substantially preserve pair-wiseinstallation of single width 16 port modules in the same position as adual width 32 port modules.

FIG. 6B illustrates an embodiment utilizing a unique chassis bulkheadmounting configuration for splitter modules in combination with a uniquelatch configuration associated with the splitter module to ensure thattwo single-width sixteen port splitter modules 260 are installed in apair wise arrangement into the same space that would otherwise accept asingle width thirty-two port splitter module 254. FIG. 6B includes abulkhead 250 having an upper mounting rail 251A and a lower rail 251Bdefining an opening 257 for receiving double width splitter modules 254and single width splitter modules 260. Double width modules 254 includeupper mounting hole pair 256A, lower mounting hole pair 256B on afaceplate along with a first bank of receptacles 255A and a second bankof receptacles 255B. Single width modules 260 include an upper mountinghole 261A and a lower mounting hole 261B and a single bank ofreceptacles 263. In addition, single width modules 260, and/or doublewidth mounting modules 254 may include mounting latches.

An FDH chassis is supplied with a bulkhead 250 that provides an opening257 for receiving splitter modules 254, 260 in combination with mountingholes that receive splitter module latches immediately above and belowthe opening in the bulkhead. The pattern for the module mounting holeson the bulkhead of the FDH chassis consists of four holes per doublewide module 254 which is divided into two holes on top 256A and twoholes on the bottom 256B of the opening. The configuration is uniquelyarranged such that each set of holes is offset toward the center so thatthey are not spaced evenly in the center where normally they would beexpected when mounting single-width 16 port modules 260 into the samespace. This unique bulkhead mounting arrangement ensures that a doublewidth module 254 cannot be installed immediately adjacent to a singlewidth module 260 unless two single width modules 260 have been installedin a pair wise arrangement. By ensuring a pair wise installation this inturn forces the proper utilization of the storage area for splitteroutput pigtail breakout devices on the FDH chassis which are locatedremotely from the splitter modules at a fixed distance from the splittermodule along the circumferential length.

To ensure proper mounting, a 16 port single-width module 260 is equippedwith a uniquely shaped indexing latch feature at the top and bottom ofthe module so that the single width module 260 can be installed into thebulkhead opening while allowing the latch to be slightly offset to theleft or to the right. The unique latching feature is a physically shapedbilobar hole 261A, 261B that allows the latch of single width module tobe shifted to the left or to the right upon installation to align withthe off center holes.

Additionally, the slotted hole on the single-width module 260 isuniquely shaped to allow a standard fastener typically used for thistype of module to be fixed in place either to the left or to the right.This slotted hole is configured in a unique heart or bilobar shape so asto latch the fastener grommet either to the right of center when thesingle-width module is mounted in the left position or to the left ofcenter when the single-width module is mounted to the right position.The heart shaped slot essentially indexes the latch to the left or tothe right while retaining adequate strength to seat the grommet and tolocate and secure the module firmly in place without subsequent shiftingwithin the bulkhead opening.

FIGS. 6C-6H illustrate aspects of the keying mechanism used for aligning16 and 32 output splitter modules in a desired pattern.

FIGS. 7A-7E illustrate views of a fiber distribution hub in accordancewith an embodiment of the present invention. The FDH in accordance withan embodiment administers connections between fiber optic cables andpassive optical splitters in the Outside Plant (OSP) environment. Theseenclosures are used to connect feeder and/or distribution cables viaoptical splitters to provide distributed service in a FTTP networkapplication. The preferred embodiment FDH provides across-connect/interconnect interface for optical transmission signals ata location in the network where fiber hubbing, operational access andreconfiguration are important requirements. In addition the FDH isdesigned to accommodate a range of sizes and fiber counts and supportfactory installation of pigtails, fanouts and splitters.

In accordance with preferred embodiments, the FDH is provided in polemount or pedestal mount configurations. The same cabinet and workingspace is available in both pole mount (FIGS. 7A and 7B) and pedestalmount units (FIGS. 7C, 7D and 7E). Three sizes of FDHs are typicallyavailable, for example, to correspond to three different feeder counts,for example, 144, 216 and/or 432; however, additional sizes of FDHs canbe used without limitation.

Embodiments of 280, 290, 300, 310, 320 FDH provide termination,splicing, interconnection and splitting in one compartment. Theenclosures accommodate either metallic or dielectric asp cables viasealed grommet entry. Cables are secured with standard grip clamps orother means known in the art. The FDH may also provide grounding formetallic members and for the cabinet.

Enclosures 280, 290, 300, 310, 320 provide environmental and mechanicalprotection for cables, splices, connectors and passive opticalsplitters. These enclosures are typically manufactured from heavy gaugealuminum and are NEMA-3R rated and provide the necessary protectionagainst rain, wind, dust, rodents and other environmental contaminants.At the same time, these enclosures remain lightweight for easyinstallation, and breathable to prevent accumulation of moisture in theunit. An aluminum construction with a heavy powder coat finish alsoprovides for corrosion resistance. These enclosures are accessiblethrough secure doors that are locked with standard tool or pad-lock.

FIG. 8 illustrates a view of the internal components of a fiberdistribution hub enclosure 350 in accordance with an embodiment of thepresent invention. FDH enclosure 350 can be configured in a number ofdifferent ways to support fiber cable termination and interconnection topassive optical splitters. The configuration illustrated in FIG. 8provides for a termination shelf 352, a splitter shelf and opticalcomponent modules 354, a splice shelf 356, and a channel for fibermanagement 358.

Termination shelf 352 can be based on the standard main distributioncenter (MDC) enclosure line that provides complete management for fiberterminations in accordance with an embodiment of the present invention.The termination shelf may be preterminated in the factory with a stubcable containing, for example, 72, 144, 216, 288 or 432-fibers. Thisstub cable is used to connect services to distribution cables routed toresidences. The distribution fibers are terminated on certifiedconnectors. The termination shelf may use standard 12-pack or 18-packadapter panels, for example, that have been ergonomically designed toprovide easy access to fiber terminations in the field. These panels canbe mounted on a hinged bulkhead to allow easy access to the rear formaintenance. The fiber jumpers are organized and protected as theytransition into the fiber management section 358 of the enclosure.

The splitter shelf 354 can be based on a standard fiber patch panel thataccepts standard optical component modules (OCM) holding opticalsplitters in accordance with a preferred embodiment of the presentinvention. In a preferred embodiment, the splitter modules, orcassettes, are designed to simply snap into the shelf and therefore canbe added incrementally as needed. The splitter shelf 354 serves toprotect and organize the input and output fibers connected to thecassettes. Splitter shelves 354 are available in various sizes and theshelf size can be optimized for different OCM module configurations.

FIG. 9 illustrates a schematic view of a fiber distribution hubenclosure 380 having a side-by-side equipment configuration inaccordance with an embodiment of the present invention. There are twoadjacent termination shelves 388, 390 and two adjacent splitter shelves384, 386, separated by a central fiber management channel 382 inaccordance with an embodiment of the present invention.

FDHs may be installed on utility poles or in pedestal arrangements thatrequire the rear of the enclosure to remain fixed. In these situations,it is not possible to access cables or fiber terminations through therear of the cabinet. Normal administration of an FDH may require that alinesman access the rear of the termination bulkhead to performmaintenance operations on the rear connectors. One such operation iscleaning a connector to remove dirt and/or contamination that mightimpair the performance of components therein. In addition, the rear ofan FDH enclosure may have to be accessed for trouble shooting fiberssuch as may occur with fiber breakage or crushing of a fiber.Furthermore, it may be necessary to access the rear of the enclosure foradding cables as in a maintenance upgrade or as is the case whenperforming a branch splice to route designated fibers to alternatelocations using an FDH as a point of origin. In circumstances such asthose identified immediately above, access to the rear of the enclosuremay be difficult if a rear door or access panel is not provided. Gainingaccess to the rear of such an enclosure may require disassembly of theequipment chassis and/or cabling apparatus to provide access to thefiber connectors or cables.

Arrangements for providing access behind the chassis must be carefullyplanned so as to minimize the movement of working fibers. For instance,an arrangement may be devised to move the terminations and not thesplitter pigtails. Such an arrangement may place undue stress on theterminations and/or pigtails because one section of the apparatus ismoved, while another remains stationary. Apparatus that include partialmovement to access connectors may not be suitable for adding additionalcapacity to and maintenance of, the cabling system. Sliding apparatustrays or tilting bulkhead panel apparatus may tend to create stresspoints in fiber cables and block certain other areas of the chassis formaintenance access, and therefore may not be a desirable alternative toenclosures having removable back panels.

FIG. 10 illustrates a preferred embodiment of an FDH enclosure 301 thatis designed with a unique swing frame chassis 322 that swings the entirechassis including optical connectors, splitters and splices open 90degrees or more to allow access to all optical components for cleaningand testing and to cables for maintenance or additions. The swing framedesign provides the necessary provisions to add additional cables intothe unit for future use which may require complete access to the back ofthe cabinet. For example, access to rear penetrator punch-outs 320 ispossible with the swing chassis in the opened position. Weather prooffeed-throughs can be installed when the punch-outs are removed andmulti-fiber cables can then be passed through the feed-throughs and intothe enclosure.

An embodiment of FDH cabinet 301 may be equipped with a single pointswing frame release latch 326 that provides easy access to the rear andsecurely locks the chassis into place when closed. Release latch 326 maybe positioned as shown in FIG. 10 and/or release latch 326 may bepositioned in a lower portion of the enclosure. In addition, locks canbe provided to hold the chassis open at various angular increments toreduce the chances of injury to a linesman when working on componentslocated behind the bulkhead 335. Chassis 322, when equipped with locksfor holding it open, is referred to as a self-locking chassis. In theembodiment of FIG. 10, the entire chassis is hinged providing a singlepoint of flex for a fiber cable routed to the chassis. This hinge pointis constructed in the factory to control the fiber bend; and, thereforethe fiber bend at the hinge point is not subjected to craft handling inthe field. In particular, chassis hinge 324 and cable routing hardwareare designed to ensure that manufacture recommended bend radii are notviolated when the chassis is opened or closed. For example, chassis 322may have pigtail channels 153A, B attached thereto so that the slackassociated with the pigtails remains fixed as chassis 322 is movedthroughout its range of motion.

In addition, transitions 131 and transition storage area 133 can belocated on chassis 322. In this configuration, transitions 131 may beaccessed from above when chassis 322 is in an open position. In order toensure that input fibers and pigtails are not disturbed or distorted inan impermissible manner, enclosure 300 may be configured at a factory,or plant, so as to have cable bundles dressed around hinge 324.Preconfiguring enclosure 300 reduces the chance that cabling will bedone incorrectly.

In particular, a preferred embodiment of enclosure 301 includes, amongother things, a top panel 302, a first side panel 304, a second sidepanel 306, a bottom panel 308, a back panel 309, a first door 310 and asecond door 312 which collectively make up the exterior dimensions andstructure of the enclosure 301. In addition, enclosure 301 may includeone or more carry handles 318 for facilitating deployment of enclosure301 at a desired location. First and second doors 310 and 312 may eachbe pivotally mounted by way of a hinged edge 313, 315 to facilitateaccess to components mounted within enclosure 301. In addition, firstand second doors 310, 312 may employ a lip 316 and channel 314 assemblyto facilitate tamper resistance and weatherproofing. Channel 314 mayoperate in conjunction with elastomeric gasket material to furtherfacilitate a weatherproof seal. Enclosure 301 may further include ledge307 running along an interior portion of top surface 302, first sidesurface 304, second side surface 306 and bottom surface 308 toadditionally facilitate a weatherproof seal when first and second doors312, 314 are closed. A lock 311 can be installed in a door to discourageunauthorized access to the interior volume of enclosure 301.

Enclosure 301 includes a swinging frame 322 that is hinged along a sideusing hinge 324. Hinge 324 allows frame 322 to be pivoted so as to causethe side opposing hinge 324 to move away from the interior volume ofenclosure 301. When frame 322 is in the open position, as shown in FIG.10, rear feed throughs 320 are accessible along with cable managementtray 328, splitter chassis rear cover 330 and rear terminationconnections 332.

In contrast, when swing frame 322 is in the closed position, onlycomponents on front bulkhead 335 are readily accessible. For example,termination field bulkhead 334 and splitter chassis bulkhead 336 areaccessible when swing frame 322 is in the closed position.

The trend to higher capacity fiber distribution hubs may createadditional concerns regarding rear access to optical components andcables. Along with other dimensions of the enclosure the width of thechassis may have to be increased to accommodate increased terminationcapacity that includes an increased number of connectors, splittermodules, splices and/or fiber jumpers. In addition to the issuesdescribed in conjunction with the swing frame chassis of FIG. 10,additional issues may arise as the width of a swing frame FDH chassis322 is increased.

As the width of the swing frame chassis 322 is increased the width ofthe cabinet must be increased proportionately to accommodate clearancebetween a swing frame chassis and the side wall of the enclosure as thechassis swings open. At a certain point the width of the entire cabinetgrows beyond conventionally acceptable widths, especially for utilitypole installations, when the swing frame chassis is utilized therein.While the chassis width needs to be increased to accommodate, say forexample, a larger termination field, proportionally increasing the sizeof the swing frame chassis may not be acceptable due to the addition ofeven more width to the enclosure to accommodate a swinging frame.

FIG. 11A illustrates an embodiment of a fiber distribution hub 383capable of accommodating large termination fields and large swingingframes associated therewith while minimizing the additional enclosurewidth necessary to accommodate swing frame chassis 322. Hub 383 may bean enclosure and may include, among other things, a rear enclosureportion 387, a front enclosure portion 385, a seam 381 and one or moreaccess door panels 389A, 389B. Hub 383, as illustrated, includes a firstaccess door 389A and a second access door 389B. Hub 383 includes a splitenclosure designed with a seam 381 running along substantially theentire side wall, top wall, and bottom wall. Seam 381 facilitatesseparation of front section 385 from rear section 387. Seam 381substantially splits the entire enclosure and thus provides a reductionin the overall enclosure width needed to accommodate implementations ofswing frame chasses 322. Implementations of enclosures that do notemploy seam 381 may require additional width to allow clearance betweenthe swing frame chassis and the side of the enclosure. The splitenclosure implementation of FIG. 11A is accomplished using astrengthened back section 387 that operates as a fixed structural memberof the enclosure. Seam 381 splits the enclosure at a position along thedepth to provide enough side wall stiffness to the back section 387 soas to ensure structural integrity for the entire chassis via backsection 387 and a strengthened hinge 391.

Since an FDH is typically an environmental enclosure, seam 381 in theenclosure must be sealed to protect against water and otherenvironmental factors. Thus the rear enclosure portion 387, the frontenclosure section 385, and the chassis are joined with a compressionseal via seam 381 that serves as an environmental barrier. To accomplishenvironmental sealing, hinge 391 is located outside seam 381 so that acontinuous seal may be routed around the enclosure. In addition theentire back section 387 of the enclosure may be covered by rain shield393 that operates as a roof for the enclosure including the splitsection. Hinge 391 is designed and configured so as to manage the bendradii of fibers in an acceptable manner.

Furthermore front enclosure portion 385 and rear enclosure portion 387are joined by two quick release latches located within the enclosure andaccessed only through the front doors. These latches actuate a releasethat allows separation of the chassis section away from the rearenclosure portion 378 to provide access to the enclosure. The latchesdraw the enclosure back together and provide compression against seam381 to provide an environmental seal. FDH 383 may further be equippedwith angled cable entry channels for carrying moisture away from thecable seals. The angled entry way, if employed, is associated with arear section of the enclosure.

Rear enclosure portion 387 may provides a unique cable management schemeto provide rear and/or side entry. Rear entry is provided in much thesame way as conventional enclosures via an angled fixture to carrymoisture away from the cable seals. The back section of the splitenclosure is designed so that the side sections are large enough toaccept the same fixtures thus allowing side cable entry into theenclosure as well.

FIGS. 11B-11G further illustrate embodiments of split enclosures. FIG.11B illustrates a top view of an enclosure 440 showing top surface 442consisting of a rain shield 446. FIG. 11C illustrates a view showingrear surface 444 and utility pole mounting brackets 445A-D. FIG. 11Dillustrates a side view of an enclosure showing rain shield 446, frontportion 448, central portion 447 and rear portion 444. In the embodimentof FIG. 11D, rear portion 444 remains fixed by way of being supportedon, for example, a utility pole. Central portion 447 is pivotallyattached to rear portion using a hinge and front portion 448 ispivotally attached to central portion 447 using hinge 450. FIG. 11Eillustrates a front view of an enclosure 441 showing, among otherthings, an optical splitter mounting area 456, a subscriber terminationfield 458, a cable raceway 454 and a first door 452A and a second door4528. FIG. 11F illustrates an enclosure 459 having rear portion 444 andgasket 450 pivotally attached to central portion 447. Central portion447 is in an open position and is disengaged from rear portion along,for example, three edges. Enclosure 459 may further include shelves 460,optical splitter module mounting areas, subscriber termination fields,etc. FIG. 11G illustrates a perspective view showing the rear portion ofenclosure 459. Latches 464 retain central portion 447 in a closedposition.

FIGS. 11H and 11I, together, illustrate an exemplary method for usingembodiments of FDH enclosures employing one or more swinging chasses.First, a determination is made as to whether the enclosure utilizes aswinging chassis 322 (step 337). If no swinging chassis is used, theenclosure is accessed using conventional techniques known in the art(step 339). If a swinging chassis 322 is identified in step 337, adetermination is made as to whether the enclosure is a split enclosure(step 341). If the enclosure is not a split enclosure, the enclosuredoors are opened (step 343) and the method flow goes to the input ofstep 351. In contrast, if a split enclosure is identified in step 341,the enclosure doors are opened (step 345) and then one-or-morecompression latches are released (step 347).

Compression latches are used to keep the gasket of the enclosure incompression to facilitate weatherproofing. After the compression latchesare released, the moveable portion of the enclosure is moved to itsopened position (step 349). For example, a first section 448 and/or acentral section 447 may be pivoted in an open position. After step 349,the method flow from the No path of step 341 rejoins the main methodflow. The swinging chassis 322 is unlatched (step 351) and the chassisis pivoted to an open position (step 353).

After the chassis is in the open position, a determination is made as towhether the chassis frame is equipped with a locking mechanism to keepthe frame at a desired angle with respect to the enclosure (step. 355).

If no locking mechanism is present, the method flow goes to the input ofstep 359. In contrast, if a locking mechanism is present, the lock isengaged to hold the open chassis at a determined position (step 357).Next, a desired service is performed (step 359). By way of example, adesired service may include repairing damaged or worn components withinthe enclosure, inspecting components within the enclosure, connecting asubscriber, disconnecting a subscriber, adding additional components,such as optical splitter modules to the enclosure, and/or removingcomponents from the enclosure.

Now referring to FIG. 11I, after service is performed, a determinationis made as to whether the chassis frame is locked in an open position(step 361). If the chassis is not locked in the open position, methodflow goes to the input of step 365. In contrast, if the frame is lockedopen, the lock is released (step 363). The chassis is then closed (step365) and latched in the closed position (step 367).

A determination is then made as to whether a split enclosure is in theposition (step 369). If a split enclosure was not used, method flow goesto the input of step 375. In contrast, if a split enclosure was used andis open, the appropriate enclosure section is closed (step 371) and thecompression latches are engaged (step 373). The doors to the enclosureare then closed (step 375) and locked if needed.

FDH enclosures are commonly mounted to utility poles at an elevationthat cannot be accessed by a linesman standing on the ground; andtherefore, the linesman typically accesses the enclosure by climbing tothe elevation of the enclosure. Often, enclosures are installed inconjunction with a utility platform or balcony that is a substantiallypermanent fixture attached to the pole below the enclosure that allowsthe linesman to stand in front of the enclosure while making circuitconnections. A linesman may climb a ladder or steps to the elevation ofthe balcony and then transfer to the balcony to conduct operations.Standard safety procedures used in the art require that the linesmanlatch into appropriate safety mechanisms in conjunction with a safetyharness to break a fall should a fall occur while climbing the ladder,transferring to the balcony, or while working on the platform.Provisions for safety latching and access are typically provided alongwith enclosure installations such as FDH installations.

Enclosures fabricated for use in copper plant installations (such asplain old telephone system, or POTS installations) were typicallyfabricated from heavy gauge steel and thus provided adequate strengthfor latching safety harnesses directly to the enclosure. However, newenclosures are constructed from aluminum or other lightweight,corrosion-resistant materials to provide easier installation and toprovide added protection against long term exposure to the elements.These lightweight enclosures do not provide adequate structural strengthto reliably break a fall if a safety line is attached thereto.

In typical field operations, a linesman may transfer from a ladder tothe platform, or balcony, to begin work on an elevated enclosure. Safetyprocedures dictate that the linesman first attaches a safety line to anappropriate structure, herein a latching point, on the pole beforemaking the transfer. In order to encourage attachment of the safety lineto the latching point that is easily accessible, and optimally locatedwith respect to the linesman while on the ladder. In addition, thelatching point provides necessary mobility to the linesman as he/shetransfers from the ladder to the platform and while he works on theenclosure. In addition, a structural handle may be provided. Thestructural handle may be configured to support the linesman's weight asthe linesman transfers from the ladder to the platform. In addition, thehandle can be configured to withstand loads associated with a fall. Thelatching point and handle are mounted on both sides of the pole andmounted enclosure since it cannot be determined ahead of time, withcertainty, from which side of the pole the linesman will ascend to theplatform.

Preferred embodiments of an elevated FDH include a latching point inconjunction with a structural member which can be installed as an optionwith a pole mounted FDH. Use of the optional member, allows installationof a latching point equipped FDH only in circumstances where it isdesired. For those situations where a latching point is not needed, theFDH is provided with a standard mounting bracket. Still otherembodiments of the elevated FDH provide for a standard mounting bracketthat is capable of post installation augmentation by the addition of astructural member and latching point should it be desired after aninitial installation of the FDH. Since the latching point and/orstructural member may incur damage if they are used to break a falland/or over the normal course of use, embodiments of the elevated FDHutilize field-replaceable latching points and/or structural members.

FIG. 12A illustrates a preferred embodiment of an elevated FDH 399mounted to a utility pole 401 using a structural member 404 having alatching point 400. FDH 399 may include an enclosure 403, structuralmember 404, mounting bracket 410 and lower mounting bracket 412.Structural member 404, may serve as stabilization member and/or mountingbracket that can optionally be equipped with a latching point 400attached to structural member 404. In addition, a handle 406 can bereleasably attached to the enclosure mounting bracket 410 using bolts408. The structural member 404 may be constructed, for example, from asteel beam such as a welded beam and may provide adequate strength totransfer the load of an accidental fall directly to the utility pole 401without relying on the strength of elevated FDH enclosure 403. In apreferred embodiment, structural member 404 may span substantially theentire width of the enclosure 403. In addition, latching points 400 arelocated so that a linesman can access them from the front, side, and/orback of FDH 399. Furthermore, latching points 400 are located so that asafety line can be draped over a door 414, 416 of FDH 399 while alinesman works inside enclosure 403. While steel is used in a preferredembodiment of the structural member 404, other materials such asaluminum, titanium and/or composite can be used for the beam if desired.Material cross sectional dimensions may be altered appropriately for thespecific materials to achieve a determined load bearing capacity.Implementations of FDH 399 may employ structural member 404 havingshapes other than that shown in FIG. 12A. Structural member 404 may bemounted directly to pole 401 or it may be mounted to an interveningstructure which is in turn mounted to pole 401. Additionally, stabilizerbar 404 can be demounted as desired.

In the embodiment of FIG. 12A, the latching point consists of a safetyring 400 made from, for example, a structurally sound “D-Ring” loop thatis sized to allow fastening of the standard linesman's safety harnessthereto and further having sufficient strength to restrain a linesmanunder accidental fall conditions. Latching point 400 is replaceable andmay be specified to be replaced after a single fall. As such, thelatching point 400 is designed to be easily replaced using fasteners,such as bolts 401, in conjunction with bracket 402. A handle 406 is alsoprovided in the illustrated embodiment. Handle 406 may fasten onto aside of the pole mount bracket to facilitate a linesman's transfer froma ladder to a platform. In particular, handle 406 may be mounted to aflange 410 on structural member 404 and is positioned to assist alinesman while transferring from the ladder to the pole 401. Forexample, a linesman climbing the pole 401 will latch the safety harnessto the latching point 400, and then hold the handle 406 whiletransferring from the ladder to a secure position on the balcony infront of the elevated FDH enclosure.

A typical installation of the elevated FDH 399 will include a latchingpoint 400 and a handle 406 mounted on either side of the FDH 399. Tohelp ensure the safety of the linesman, handle 406 may be designed sothat it will not accept the latch from the linesman's safety harnessbecause handle 406 may not rated for an accidental fall load. Thissafety feature is achieved by increasing the diameter of handle 406beyond a diameter that will function with the safety latch on thelinesman's harness while still keeping the diameter of the handle withinan acceptable range for a typical linesman to grasp. As a result, alinesman may be forced to connect the safety latch on the harness toonly devices rated for a fall, such as latching point 400.

FIG. 12B illustrates an exemplary method for using an elevated FDHenclosure 399 equipped with a handle 406 and latching point 400. Themethod of FIG. 12B commences when a linesman places a ladder against autility pole 401 having an elevated FDH 399 mounted thereto (step 420).The linesman climbs the pole to the height of a balcony associated withelevated FDH 399 (step 422). Then the linesman attaches a safety line,rated for stopping a fall, to latching point 400 (step 424). Thelinesman then grasps handle 406 and transfers from the ladder to thebalcony (step 426).

Once on the balcony, the linesman opens doors 414 and 416 to gain accessto components located within an interior volume of elevated FDH 399(step 428). Any necessary servicing is performed (step 430) and thendoors 414, 416 are closed (step 432). The linesman then grasps handle406 and transfers to the ladder (step 434). The safety line is unclippedfrom the latching point 400 (step 436) and the linesman descends theladder (step 438).

FIG. 13 is a flow chart illustrating a method for installing andconnecting optical splitter module pigtails in accordance with apreferred embodiment of the present invention. The method includes thestep 522 of installing a splitter module with output pigtails in a patchpanel position. Further, the method includes the step 524 of routing thesplitter module output pigtails circumferentially around a subscribertermination field. The method includes the step 526 of connecting anindividual splitter pigtail connectorized ends at splitter modulestorage receptacles. These storage receptacles can initially bepreconditioned in the factory. The method includes a next step 528 ofstoring the pigtail slack in half-loops in an adjacent vertical channel.Further, the method includes the step 530 of deciding whether to connector disconnect the service order. If a service order needs to beconnected, the method includes the decision in step 532 of determiningif a splitter output is available for assignment. If it is determinedthat the splitter output is available for assignment then the methodprogresses to step 542 of disengaging connectorized pigtail from thestorage position. If it is determined that the splitter output is notavailable per step 538 then it is determined if a position is availablefor adding a module. If Yes, then the method steps are reiteratedstarting back from step 522. If, however, it is determined that there isno position available then the maximum module capacity of the system hasbeen reached.

The method also includes the option of disconnecting the service orderper step 530. The step 534 includes disengaging the connectorizedpigtail from the subscriber position and per step 536 routing thepigtail through an expanded circumferential path around the subscribertermination field 536.

The method further includes the step 544 of connecting the splitterpigtail to the subscriber position and the step 546 of routing thepigtail through a reduced circumferential path around the subscribertermination field. The method includes the step 548 of storing thepigtail slack in graduated half-loops in an adjacent vertical channel.

Alternative embodiments for interior components of FDHs may be practicedin accordance with teachings herein. By way of example, hinged parkingpanels may be employed for storing unused pigtails. FIG. 14A illustratesa chassis 600 utilizing hinged parking. The embodiment of FIG. 14A mayinclude, among other things, a chassis frame 602, module retainers 603,a splitter module mounting area 604, an upper splitter module shelf 605,a mounting bracket 606 for pivotally mounting chassis frame 602 andstorage/parking panel 612 to an interior surface of an enclosure, aninner volume 608, a storage panel hinge 610, storage parking panel 612,a parking portion having a plurality of receptacles 614, fiber pigtailguides 616, a fiber pigtail guide panel 618, a storage panel primaryguide 620, and a chassis fiber guide 622.

Chassis frame 602 has an inner volume 608 for accepting a subscribertermination field. Chassis 602 also includes a splitter module shelf 605for supporting splitter modules above a subscriber termination field.Splitter modules are retained in place using retainers 603. Retainer 603may be, for example, thumb screws. Fiber pigtails having connectorizedends, are routed through chassis cable guide 622, panel primary guide620, and one-or-more panel mounted fiber pigtail guides 616 before beingstored in parking receptacle field 614 via a connector on a pigtail.

Hinged storage/parking panel 612 may provide greater fiber connectordensity than embodiments utilizing splitter modules having storagereceptacles thereon, such as on an optical splitter face plate. Hingedstorage/parking panel 612 may also provide greater fiber connectordensity than embodiments utilizing splitter modules located below asubscriber termination field. In addition, storage receptacles 614 canbe organized in columns of 16 or 32 receptacles so as to correspond to asplitter module having 16 or 32 pigtails. As pigtail connectors areremoved from storage receptacles 614 and deployed onto the subscribertermination field, columns of receptacles can be removed from hingedpanel 612 and re-used in FDHs at other locations. Furthermore, once allpigtails are deployed on the subscriber termination field, the entirehinged panel 612 can be removed thus providing unencumbered access tothe subscriber termination field. In addition, hinged panel 612 can besized to serve as a protective cover for the subscriber terminationfield. If gasketing, or other releasable sealing means, is provided,then hinged panel 612 can operate to prevent dust and debris fromaccumulating on the subscriber termination field.

FIG. 14B illustrates an embodiment of a chassis having two doorscontaining connector parking. Embodiment 650 may include, among otherthings, a chassis 651, an upper splitter module shelf 652 having a firstmodule area 656A, a second module area 656B, a first set of moduleguides 654A, a second set of module guides 654B, a first set of moduleretainers 658A, a second set of module retainers 658B, an upper chassisfiber guide 660A, a lower chassis fiber guide 660B, a first door panel662A having a lower parking management area 666, an upper parkingmanagement area 664, an upper and lower parking field 668, 670, panelupper fiber guides 672, panel lower fiber guides 674, an inner volume680 and a second door panel 662B having substantially the sameconfiguration as the first door panel 662A. The embodiment of FIG. 14Boperates in substantially the same manner as the embodiment of FIG. 14Aexcept that the receptacles for parking splitter module outputs arecontained on two hinged door panels 662A, 662B. The chassis embodimentsof FIGS. 14A and 14B may be used with enclosures mounted on grade aswell as enclosures supported on utility poles.

FIG. 15 illustrates an exemplary implementation of an equipmentenclosure employing hinged parking. Enclosure 1500 may include a firsthinged door 1502, a second hinged door 1504, a first set of parkingadapters 1506, a second set of parking adapters 1508, a first set offiber channels 1510, a second set of fiber channels 1512, a firstenclosure door 1514, a second enclosure door 1516, and a first hinge1518.

Enclosure 1500 may include a fiber distribution hub as previouslydescribed herein. Enclosure 1500 may be mounted on a utility pole atground level or near the top of the utility pole. In addition, enclosure1500 may be mounted on the ground and/or in a below grade vault. Firstand second enclosure doors 1514 and 1516 may serve as the primary accessto the interior of enclosure 1500. While the implementation of FIG. 15illustrates an enclosure having two enclosure doors, otherimplementations may include a single enclosure door.

Enclosure 1500 may include a first hinged door 1502 and a second hingeddoor 1504 configured and adapted to hold one or more parking adapters.First and second hinged doors 1502, 1504 may be substantially flat andmay include cutouts, or panel openings, for accepting parking adapters1506, 1508. First and second hinged doors 1502, 1504 may also includefiber channels 1510, 1512 for routing optical fibers associated withconnectors that may be plugged into parking adapters 1506, 1508. Firstand second hinged door 1502, 1504 may be pivotally supported onenclosure 1500 and/or enclosure doors 1514, 1516 using one or morepivoting devices, such as hinges 1518 and 1520 (not shown).

FIG. 16 illustrates an exemplary implementation of a parking adapter1600 that may be used in conjunction with first hinged door 1502 and/orsecond hinged door 1504 consistent with the principles of the invention.Parking adapter 1600 may include any device capable of receiving aconnector associated with a fiber optic cable and/or an adapter dustcap. For example, parking adapter 1600 may be configured and adapted toreceive SC connectors LC connectors, and/or other connectors known inthe art. Parking adapter 1600 may also be configured and adapted toreceive SC and/or LC dust caps and/or SC or LC adapter dust caps.Implementations of parking adapter 1600 may include 16 adapters arrangedin a row and/or column; however, other implementations may include feweradapters, more adapters, and/or adapters arranged in multiple rowsand/or columns. Parking adapter 1600 may be installed in a verticaland/or a horizontal orientation within an enclosure, such as enclosure1500. Parking adapters 1600 may be configured and adapted to mountwithout tools and/or fasteners, and/or parking adapters 1600 may beconfigured to mount via fasteners, such as screws, rivets, tie wraps,adhesive bonding techniques, etc. Parking adapter 1600 may be made fromplastic, metal and/or composite, via injection molding and/or machiningoperations.

Parking adapter 1600 may include a base 1602, a lower engagement tab1604, an upper engagement hook 1606, a dust cap post 1608, an adapterparking receptacle 1610. Parking adapter 1600 may be adapted to operatewith a surface, such as a panel associated with first hinged door 1502and/or second hinged door 1504. Parking adapter 1600 may be supported ona panel via a lower panel opening 1612A and/or an upper panel opening1612B. Base 1602 may include a substantially flat surface that isadapted to rest against a panel, such as a door panel associated withhinged door 1502 and/or 1504 when parking adapter 1600 in installedthereon. Lower engagement tab 1604 may be configured and adapted toengage lower panel opening 1612A to removeably support a lower portionof parking adapter 1600 when installed on hinged door 1502 and/or 1504.

Upper engagement hook 1606 may include any device capable of retainingan upper portion of parking adapter 1600 in a determined location. Forexample, in one implementation upper engagement hook 1606 may beconfigured and adapted as a tensioned hook that exerts an upward forceon a portion of upper panel opening 1612B when operatively engagedtherewith. Upper engagement hook 1606 may be disengaged from hinged door1502 and/or 1504 by applying, for example, a downward pressure whilepulling the upper portion of parking adapter 1600 away from hinged door1502 and/or 1504. Substantially any number of parking adapters 1600 maybe positioned alongside each other to accommodate substantially anynumber of parked connectors and/or adapter dust caps.

Parking adapter 1600 may include one or more dust cap posts 1608. Dustcap post 1608 may be configured and adapted to receive a connector dustcap that has been removed from a connector associated with an opticalfiber. For example, dust cap post 1608 may be adapted to receive an SCdust cap and/or an LC dust cap. Dust cap post 1608 may provide aconvenient location for retaining dust caps until they are needed toprotect an optical fiber associated with a connector, such as when aconnector is removed from a subscriber port. Implementations of dust cappost 1608 may be tapered and/or stepped to accommodate more than onetype of dust cap.

Parking adapter 1600 may include one or more adapter parking receptacles1610 that may be configured and adapted to receive a connectorassociated with an optical fiber, such as a fiber pigtail associatedwith an optical splitter. For example, implementations of parkingadapter 1600 may be configured and adapted to receive an SC and/or LCconnector. Adapter parking receptacle 1610 may be dimensioned to providea relatively secure fit for connectors coupled thereto in order toprevent dirt and/or moisture from reaching internal portions of theconnector and/or fiber housed therein. For example, adapter parkingreceptacle 1610 may be configured and dimensioned to be slightly largerthat the dimensions of a connector associated with an optical fiber toas to discourage debris from passing through a gap between thereceptacle surfaces and the connector surfaces.

FIG. 17 illustrates an exemplary parking adapter including an adapterdust cap and connector dust cap along with a parked connector having anoptical fiber associated therewith. Parking adapter 1600 may include aconnector dust cap 1702 removeably supported on dust cap post 1608 whenconnector dust cap 1702 is not in use on a connector. Connector dust cap1702 may include SC, LC and/or other types of connector dust caps thatmay be used in conjunction with optical fibers. Parking adapter 1600 mayalso operate with a fiber optic connector 1708 having a boot 1710, andan optical fiber 1712 associated therewith. Fiber optic connector 1708,boot 1710 and optical fiber 1712 may be associated with providingservice to a subscriber in conjunction with, for example, a subscribertermination shelf or field, such as subscriber termination shelf 352(FIG. 8).

Fiber optic connector 1708 may include any type of connector capable ofcoupling an optical signal from an optical fiber to a receptacle and/oranother connector. Fiber optic connector 1708 may include an LC, SCand/or other types of suitable connectors. Boot 1710 may be locatedproximate to a transition from connector 1708 to fiber 1712 and mayserve to join the connector and fiber and may also serve to manage abend radius associated with optical fiber 1712.

Parking adapter 1600 may include adapter parking receptacles 1610 thatare configured and adapted to receive adapter dust caps 1706 when theyare removed from a subscriber termination field or panel. For example,an FDH may include a subscriber termination panel that is equipped withadapter dust caps 1706 until a subscriber is connected to a source viaan operational optical connection, such as by way of a fiber pigtailhaving a connector and optical fiber associated therewith. When asubscriber is connected to a subscriber termination, an adapter dust cap1706 that was protecting the termination may be removed and placed intoadapter parking receptacle 1610. By way of example, a connector 1708 andfiber 1712 may be removed from adapter parking receptacle 1610 andconnected to a subscriber termination. An adapter dust cap from thatsubscriber termination may be installed in the adapter parkingreceptacle that previously housed the connector associated with therecently connected subscriber.

Parking adapter 1600 may be removed from an enclosure when allconnectors associated with the adapter are in use to convey opticalsignals to subscribers. When all parking adapters 1600 associated with ahinged door 1502, 1504 are no longer in use, hinged door 1502, 1504 maybe removed and reused in another enclosure. Alternatively, hinged door1502, 1504 may be augmented with flat, substantially non-porous panelsto prevent dust, dirt and/or moisture from reaching an interior portionof an enclosure when parking adapters 1600 are removed therefrom.Alternatively, blank hinged panels may be installed to prevent dust,dirt and/or moisture from reaching an interior portion of an enclosurewhen parking adapters are removed therefrom.

FIG. 18 illustrates an exemplary enclosure having stationary parkingadapters. Enclosure 1800 may include stationary adapters 1802 and a rearpanel 1804. Stationary adapters 1802 may be configured and dimensionedsubstantially as parking adapter 1600 discussed in conjunction withFIGS. 16 and 17.

Rear panel 1804 may be substantially flat and may include an upper panelopening 1808 that may be used to support a subscriber termination fieldand/or a lower panel opening 1810 that may be used to support one ormore stationary parking adapters 1802. Rear panel 1804 may operate as arear panel for an optical splitter module shelf. When optical splittersare installed, connectors associated with the splitter modules may beparked on one or more banks of stationary parking adapters 1802. Forexample, connectors associated with output pigtails 110 (FIG. 3A) may beparked on stationary parking adapters 1802. As connectors are used toconnect service to subscribers, stationary parking adapters 1802 may beremoved when no longer needed for storing unused connectors. Removedstationary parking adapters 1802 may be reused in other enclosures.

Optical fibers associated with connectors coupled to stationary parkingadapter 1802 may be run through guide channels 1806. Guide channels 1806may manage slack associated with optical fibers in an organized manneras previously described herein.

FIG. 19 illustrates an exemplary method for configuring an enclosurewith hinged parking. One or more hinged parking panels, or doors, 1502,1504 may be installed in an enclosure 1500 (act 1902). Hinged parkingpanels 1502, 1504 may be configured to open with enclosure doors 1514,1516 or may be configured to open independently. One or more parkingadapters 1600 may be installed on parking panel 1502, 1504 (act 1904).Parking adapter 1600 may have a number of adapter receptacles 1610associated therewith.

Unassigned connectors 1708, having optical fibers 1712 associatedtherewith, may be engaged with adapter receptacles 1610 (act 1906).Connectors 1708 may be stored until needed to connect service to asubscriber. Optical fibers 1712 associated with the parked connectors1708 may be routed through fiber channels 1510 to retain the fibers inan orderly arrangement (act 1908). Excess fiber 1712 associated with theparked connectors 1708 may be routed through fiber channels locatedelsewhere in the enclosure (act 1910). For example, fiber channels 1510may be configured and arranged to maintain slack in conjunction withfiber channels located elsewhere in an enclosure, such as fibermanagement guide 358 (FIG. 8), to prevent excessive bending and/orpinching optical fibers when hinged parking panels 1502, 1504 and/orenclosure access doors 1514, 1516 are opened and/or closed. Fiberchannels 1510 may also be configured and arranged to maintain slack indesired quantities, orientations and positions to facilitate maintainingan orderly fiber arrangement within an enclosure. Hinged parking panel1502 may be closed after connectors 1708 are parked and excess opticalfiber is placed in fiber channels 1510 (act 1912).

FIG. 20 illustrates an exemplary method for connecting a subscriber toan optical signal associated with an enclosure employing hinged parking.The method may commence when the enclosure door 1514, 1516 and a hingedparking panel 1502, 1504 are opened (act 2002). A parked connector 1708may be removed from parking adapter 1600 (act 2004). A connector dustcap 1702 may be removed from the connector (act 2006). Connector dustcap 1702 may be placed on dust cap post 1608 to retain the removed dustcap 1702 in a known location for future use (act 2008).

An optical fiber 1712 associated with the removed connector 1708 may beremoved from fiber channel 1510 (act 2010). Optical fiber 1712 may berouted through one or more fiber channels 1510 in the enclosure toaccommodate management of excess fiber (act 2012). Adapter dust cap 1706may be removed from a subscriber termination in a subscriber terminationfield (act 2014). The connector 1708 that was removed from parkingadapter 1600 may be connected to the subscriber termination from whichthe adapter dust cap 1706 was removed (act 2016). When connector 1708 isplugged into the subscriber termination, communication services may beavailable to a subscriber associated with the termination. The adapterdust cap 1706 that was removed from the subscriber termination in act2014 may be inserted into the parking adapter 1600 from which theconnector 1708 was removed in act 2004 (act 2018).

A connector and fiber may be removed from a stationary parking adapterand/or a parking adapter associated with a splitter faceplate andconnected to a subscriber termination in a manner similar to thatdescribed in connection with FIG. 20.

Systems and methods consistent with the invention make possible theconfiguration of enclosures used in passive optical networks. Forexample, an enclosure may be configured to provide convenient parking ofunused connectors and/or dust caps associated with the connectors and/oradapters.

The foregoing description of exemplary embodiments of the inventionprovides illustration and description, but is not intended to beexhaustive or to limit the invention to the precise form disclosed.Modifications and variations are possible in light of the aboveteachings or may be acquired from practice of the invention. Forexample, while a series of acts have been described with respect toFIGS. 19 and 20, the order of the acts may be varied in otherimplementations consistent with the invention. Moreover, non-dependentacts may be implemented in parallel.

For example, implementations consistent “with the principles of theinvention can be implemented using connectors, receptacles, adaptersand/or routing techniques other than those illustrated in the figuresand described in the specification without departing from the spirit ofthe invention. In addition, the sequence of events associated with themethods described in conjunction with FIGS. 19 and 20 can be performedin orders other than those illustrated. Furthermore, additional eventscan be added, or removed, depending on specific deployments,applications, and the needs of users and/or service providers. Further,disclosed implementations may not be limited to any specific combinationof hardware circuitry and/or software.

No element, act, or instruction used in the description of the inventionshould be construed as critical or essential to the invention unlessexplicitly described as such. Also, as used herein, the article “a” isintended to include one or more items. Where only one item is intended,the term “one” or similar language is used. Further, the phrase “basedon,” as used herein is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

The scope of the invention is defined by the claims and theirequivalents.

1. A fiber distribution hub having a side-by-side equipment layout, thefiber distribution hub comprising: an enclosure defining an interior,the enclosure including a main enclosure body and a door connected tothe main enclosure body, the main enclosure body defining an accessopening for enabling access to the interior of the enclosure, the doorconfigured to move relative to the main enclosure body from a closedposition covering at least a portion of the access opening to an openposition; at least a first optical splitter module positioned within theenclosure, the first optical splitter module configured to receive anincoming optical signal and to split the incoming optical signal into aplurality of output signals; a plurality of pigtails extending from thefirst optical splitter module to connectorized ends, each of thepigtails configured to transmit one of the output signals from the firstoptical splitter module; a left optical termination field positionedwithin the enclosure, the left optical termination field including aplurality of fiber optic adapters, the fiber optic adapters having frontports adapted for receiving the connectorized ends of the pigtails andrear ports for receiving fiber optic connectors corresponding tosubscriber lines; a right optical termination field positioned withinthe enclosure, the right optical termination field including a pluralityof fiber optic adapters, the fiber optic adapters having front portsadapted for receiving the connectorized ends of the pigtails and rearports for receiving fiber optic connectors corresponding to subscriberlines; and a cable management region positioned between the lefttermination field and the right termination field, the pigtails beingrouted downwardly and then upwardly in a half-loop configuration withinthe cable management region.
 2. The fiber distribution hub of claim 1,further comprising: a left splitter mounting region arranged adjacentthe left termination field, wherein the first optical splitter module ismounted at the left splitter mounting region.
 3. The fiber distributionhub of claim 2, wherein the left splitter mounting region is locatedbelow the left termination field.
 4. The fiber distribution hub of claim1, further comprising: a right splitter mounting region arrangedadjacent the right termination field, wherein the first optical splittermodule is mounted at the right splitter mounting region.
 5. The fiberdistribution hub of claim 4, wherein the right splitter mounting regionis located below the right termination field.
 6. The fiber distributionhub of claim 1, further comprising: a left splitter mounting regionarranged adjacent the left termination field, wherein the first opticalsplitter module is mounted at the left splitter mounting region; and aright splitter mounting region arranged adjacent the right terminationfield, wherein a second optical splitter module is mounted at the rightsplitter mounting region.
 7. The fiber distribution hub of claim 1,further comprising a fiber optic connector storage location positionedwithin the enclosure at which the connectorized ends of the pigtails canbe stored when not received within the fiber optic adapters of the leftand right optical termination fields.
 8. The distribution hub of claim7, wherein the fiber optic connector storage location includes aplurality of receptacles each configured for receiving one of theconnectorized ends of the pigtails, and wherein the receptacles are notfunctional fiber optic adapters.